I'm really sorry. That's a tough spot to be in. Try not to blame yourself. And try not to feel guilty or selfish about anything you're feeling. Your feelings are totally valid.
Can he talk to his doctor to see if there's another medication he can try? Or is there something else that can counteract that side effect? I've been reading online, and it looks like it's more difficult to address when the cause is unknown. Being able to pin it on a medication is a good start.
You definitely aren't alone. Here is some info and stats:
http://en.wikipedia.org/wiki/Sexless_marriage
Here's Dr. Phil's take:
http://drphil.com/articles/article/60/
Here's an online group of other people in similar situations:
http://www.experienceproject.com/groups/Live-In-A-Sexless-Marriage/332
I know it's no where near being a replacement, but could you take up jogging or some other form of exercise just to have something to do with the energy? And I know it's not the same flying solo, but here's a great site for good toys: http://www.goodvibes.com
I was looking for herbs that could bring your drive down a little to make it a little less miserable. Skullcap seems like an interesting option. You can look into that.
For the intimacy part, is he willing to do anything to meet you halfway? Will he cuddle or anything? Is there something else the two of you can do together to help you stay emotionally connected while you're going through this?